gcc options for architecture and code generation for Hitachi SH

-g
The compiler debugging option, -g, is essential to see interspersed high-level source statements, since without debugging information the assembler cannot tie most of the generated code to lines of the original source file.

-mshl

Generate little-endian Hitachi SH COFF output.

-m1

Generate code for the Hitachi SH-1 chip. This is the default behavior for the Hitachi SH configuration.

-m2

Generate code for the Hitachi SH-2 chip.

-m3

Generate code for the Hitachi SH-3 chip.

-m3e

Generate code for the Hitachi SH-3E chip.

-mhitachi

Use Hitachi’s calling convention rather than that for GCC. The registers, MACH and MACL, are saved with this setting (see Calling conventions for Hitachi SH).

-mspace

Generate small code rather than fast code. By default, GCC generates fast code rather than small code.

-mb

Generate big endian code. This is the default.

-ml

Generate little endian code.

-mrelax

Do linker relaxation. For the Hitachi SH, this means the jsr instruction can be converted to the bsr instruction. -mrelax replaces the obsolete option, -mbsr.

-mbigtable

Generate jump tables for switch statements using four-byte offsets rather than the standard two-byte offset. This option is necessary when the code within a switch statement is larger than 32k. If the option is needed and not supplied, the assembler will generate errors.

Two kinds of floating point subroutines are useful with GCC.

• Software implementations of the basic functions (floating-point multiply, divide, add, subtract), for use when there is no hardware floating-point support.
• General-purpose mathematical subroutines.

GNUPro Toolkit includes an implementation of the standard C mathematical subroutine library. See Mathematical functions (math.h) in GNUPro Math Library in GNUPro Libraries.